Process and device for the filling of shells with an explosive agent containing phosphorus



Dec. 1, 1964 H. MEISSNER 3,159,075

PROCESS AND DEVICE FOR THE FILLING OF SHELLS WITH AN EXPLOSIVE AGENT CONTAINING PHOSPHORUS Filed Dec. 17, 1959 .7nven/0r:

HER/556T ME/SS IVER United States Patent 3,159,076 PROCESS AND DEVICE FOR THE FILLHNG 0F SHELLS WlTH AN EXPLOEVE AGENT CQN- TAINHNG PHOSPHORUl Heribert Meissner, Bnrbach, Kreis Siegen, Germany, as-

signor to J. Meissner, Colcgne-Eayenthal, Germany, a German f Filed Dec. 17, 1959, Ser. No. 869,271 Claims priority, application Austria Dec. 20, 1958 9 Claims. (Cl. 86-20) This invention relates to a process for filling in a hollow body with an agent by displacement from the body of an agent inert with respect to the agent to be filled in and to an apparatus for carrying out the process. More particularly, the instant invention relates to a process for packing a hollow body with an explosive or explosive mixture by displacement from the hollow body of an agent inert with respect to the explosive and to an electrically energized means for carrying out the process.

It is believed that full realization of the benefits, which can be derived from technological improvements, is not available to the art of preparing detonators, blasting caps, firing shells, grenades, mines, etc., due to the fact that the preparation of such objects is hampered by the susceptibility to untimely firing of the materials commonly used, that is, even contact with air is apt to initiate a reaction of an explosive nature.

It has been proposed to fill in hollow bodies with agents which are subject to deflagration even on contact with air, as for example phosphorus or phosphorus-containing materials, by employing as a protective (isolating) or covering agent for the phosphorus, water in the manner that the hollow body to be filled in is first filled with water and thereafter the water-filled body is dipped into a container filled with the phosphorus. The phosphorus then flows into the hollow body under the displacement of water and is then permitted to harden. While this process is comparatively simple, it is objectionable due to the fact that it does not permit control of the specific degree of filling accomplished, which factor is very important in connection with most explosives and especially in phosphorus projectiles. While it has been attempted to gauge the degree of filling by reference to the thickness of the residual layer of covering agent, this was not always satisfactory. Furthermore, there was no way of avoiding in the known processes the occurrence of cavities in the filled-in material, that is, there was no assurancethat a filling or plug of compact or compressed explosive had been obtained.

An object of this invention is to provide a process for the filling of a hollow body with asecond agent under displacement of a first agent to a predetermined level, avoiding the art disadvantages.

Another object of this invention is to provide a process for the filling of a hollow body with a second agent under displacement of a first agent to a predetermined level, the filling being regulated and controlled by the difference in the electrical conductivities of the first and second agents. I

Still another object of this invention is to provide a process permitting the uniform solidification of the second agent throughout the now filled body.

A further object of this invention is to provide an apparatus which will be suitable for use with the process of the invention.

Still a further object of this invention is to provide an apparatus for the filling of a hollow body with a second agent under displacement of a first agent to a predetermined level, the first and second agents being of different electrical conductivities, which is electrically energized.

Further objects will appear from the detailed description, taken in connection With the accompanying drawing, in which:

FIG. 1 is a longitudinal section of one example of the device in accordance with the invention;

FIG. 2 is a longitudinal section of a further example of the device in accordance with the invention; and

FIG. 3 is a longitudinal section of the device in accordance with the invention, illustrating the heating means for effecting solidification.

The process of the invention for filling a hollow body or container with a second agent, which is sensitive to air, to a predetermined level by displacement therefrom of a first agent, which is inert to said second agent and which is distinguished from the second agent by a different electrical conductivity, comprises maintaining an electric current through the said first agent at the predetermined level so that, when the first agent is displaced from that level by the second agent, the flow of current through said first agent is interrupted and must now flow through said second agent, and further controlling the supply of the second agent to the hollow body in dependence upon the difference in current, as passed through said first and second agent.

Further, in accordance with the invention, provision is made to ensure that, after the hollow body has been filled to the predetermined level with the second or filling agent, the same is allowed to solidify uniformly throughout and that no cavities are formed throughout the solidified mass. This is accomplished by maintaining the upper and central portions of the filled-in mass soft and fluid by indirectly heating these portions until the base I and outer portions of the filled-in mass have substantially completely solidified.

The process of the invention is carriedv out by first filling a hollow body or container, which may be of any dimensions and shape, variable broadly according to the specific purpose for which the filled body is intended, with an inert agent. The inert agent is any substance which is inert to the agent which is to displace it and which, of course, is not sensitive to contact with air. Furthermore, the inert agent must be capable of conducting an electric current and preferably should have a higher conductivitythan the second agent, which is to serve as the displacing and filling substance.

Water, and preferably tap water which has more electrolytes present therein, is accordingly a good electrical conductor and is an entirely suitable inert medium according to the invention.

The second agent, i.e. filling or displacing agent, may be any substance which, for example, is sensitive to air and Whose transfer from one container to another must be effected in the substantial absence of air. Examples of such substances are the readily ignitable liquid catalysts and liquid fuels so much in use today. Additional examples include the phosphorus and phosphorus-containing materials conventionally used in the explosive industry, as for instance in the manufacture of detonators, projectiles, shells, mines, etc. Preferably, the second agent is a poorer conductor of electrical current than the first agent, which it serves to displace. Most preferably, in accordance With the invention, the first agent is a good conductor, whereas the second agent is either a semi-conductor or non-conductor of electrical current.

According to the invention, the filling of the hollow body with a second agent by displacement of a first agent is accomplished with an apparatus comprising a vertically arranged hollow body or container, provided with means responsive to difference in electrical conductivity between the first and second agent, Which means are adapted to control the supply means for introducing the second agent.

The means responsive to difierence in electrical conductivity between the first and second agent is a switching device, at least one pole of the circuit of which is connected with a vertically adjustable electrode. This vertically adjustable electrode is adjusted within the hollow body at the height to which filling is to be effected. The other pole of the circuit may be a second vertically arranged electrode of somewhat shorter length, or preferably the wall of the hollow body or container may be constructed of an electrically conductive material and be connected so as to constitute a pole of the circuit of the switching device. In this instance, it is necessary to arrange only one pole of the circuit of the switching device within the shell for contact with the first or second agent.

Preferably the apparatus is provided with means for longitudinally adjusting the electrode and for fixedly maintaining the same at the predetermined level. The switching device further consists of a swtiching relay which regulates the circuit of the drive motor of a feed pump, which acts to supply the second agent. The switching relay may also control a valve or a slide serving to reguilate the supply of second agent. If a motor drive is used, the use of a brake motor is essential, as for example a brake motor provided with a shiftable slide, so that the supply of the second agent may be cut off instantaneously.

In many instances, the filling of the hollow body or container, as for example in the manufacture of projectiles, is to be regulated in such a manner that a further hollow body or container, as for example the detonator shell, may be inserted therein. In an embodiment of the invention, provision is to made for uniform solidification of the second agent throughout the container by supplying heat through the detonator shell. Thereby it is assured that the solidification takes place evenly, without cavity formation. The outside and bottom portions are permitted to solidify first, and thereafter the inner and upper portions.

It can readily be appreciated that the invention resides in a process and apparatus for filling a hollow body or container with a second agent by displacement from the hollow body of a first agent, the first and second agents being characterized by different electrical conductivities. The first and second agents serve as thebridging means for completing an electrical circuit, including a switching element which is sensitive to the difference in electrical conductivities, and which is adapted in accordance with the difference in current passed through said circuit to control the supply of the second and displacing agent.

It can also be readily appreciated that, the greater the difference between the conductivities of the first and second agent, the more simple the switching device construction can be. Highly desirable results are obtained when the second or displacing agent is either a non-conductor or a semi-conductor and when the first or inert agent is a good conductor. However, the invention is not limited to this situation.

In order to better illustrate the invention and to show how the same is to be carried into effect, reference will now be made to the accompanying drawing.

In the processes, as depicted in connection with FIG- URES 1 and 2, 1 designates a vertically arranged hollow body or container which contains the first or inert agent 3 and the second or filling agent 2, the first agent 3 and the second agent 2 being characterized by different electrical conductivities. The hollow body 1 contains a level-determining means 4, supported over and within the end portion of the hollow body by guide or slide means 10. The guide is provided with calibrated stop means 11 for arresting the longitudinal displacement of the level-determining means 4 at the predetermined level. The electric circuit, which regulates the supply of second agent, is shown at 5, the switching device at 12 and the source of current at 13.

The filling of the hollow body 1 with the first or inert agent is effected by dipping the hollow body, before the level-determining means or other connections are made, into a large vessel or chamber containing the inert material. Thereafter, the level-determining means is mounted and introduced into the hollow body and adjusted so that the filling to the predetermined level will be assured.

The second, i.e. filling or displacing, agent is fed through supply pipe 6 from a reservoir maintained out of contact with air. The supply pipe is fed from the reservoir by means of a pump 14. The pump 14 is energized via the circuit designated 15. The switch 16 for this circuit is activated by the switching device 12.

In the filling apparatus, depicted in FIG. 1, the leveldetermining means 4 comprises two poles 17 and 18,

electrically insulated with respect to one another. At least one of the poles, and preferably pole 17, extends somewhat below the lower edge of the level-determining means 4. In the embodiment, as shown in FIG. 1, the first agent 3 is a better conductor of electric current than the filling or displacing agent 2, and the electrical circuit 5 is closed, since the poles 1'7 and 18 are submerged in agent 3. In the embodiment shown in FIG. 1, the two poles are making contact only with agent 3. As the supplying of the filling agent 2 is continued, the level of the same rises. When the poles 17 and 18 are submerged in filling agent 2, the current strength in the circuit is completely changed or the same is interrupted. The switching relays 12 and 16 react and the drive circuit 15 for the pump 14, which regulates the influx of the filling agent 2, is interrupted. 1

In the embodiment shown in FIG. 2, the level-determining means 4 is provided with a contact plate at its lower edge, shown at 19, which constitutes one pole of the circuit 5. The casing of the hollow body 1, made of an electrically conductive material, serves as the second pole of the circuit 5. When the contact plate 19 is completely submerged in the filling agent 2, the required control with respect to the influx of agent 2 is shifted. Thus, when agent 2 is a non-conductor and when plate 19 is completely submerged in the agent 2, then at that moment the electrical circuit is opened and the influx of agent 2 ceases.

When the hollow body or container 1 has been filled to the predetermined level with the filling agent 2, it is in many instances important to permit agent 2 to solidify in the hollow body so that no cavities or spaces in the solidified mass are formed. In FIG. 3, the feature of the invention, which assures that such uniform solidification takes place, is shown. The hollow body 1 in FIG. 3 is shown in the approximately normally filled condition, in which it is almost filled with the filling agent 2, and only a very thin layer of the inert agent 3 remains on top of agent 2.

As shown in FIG. 3, a second hollow body or shell 7 has been inserted into the hollow body 1 in such a manner that its bottom end is submerged below the surface of filling agent 2. The hollow body or shell 7 is then screwed firmly into place. If there is required to be inserted into the solidified mass of agent 2, in addition to the shell 7, a further body, as for example the body depicted by reference numeral 20, then a corresponding prop or the actual body 21) itself is first inserted.

An outlet for gases and for inert agent 3 is provided in the collar of shell 7 at 21. This outlet allows for the removal of the inert agent 3 so that the residual amount thereof remaining will not interfere with the uniform solidification process, which is to follow, and so that no prior drawing off of the residual inert agent 3 is required.

After the insertion of the shell 7, the same is subjected to a heat treatment. This heating is most conveniently effected by any heating device conventionally known in the art and preferably by means of a heating device as shown in FIG. 3 at 9. In the embodiment shown in FIG. 3, water, designated by reference numeral 8, serves as heat carrier.

During the solidification process, the surface level of the filling agent 2 is caused to be lowered, since the solidification of the filling agent 2 is effected with shrinkage within small limits. This permits the filling up of any small cavities which may be present throughout the filling agent mass. The solidification takes place in a direction from the exterior toward the interior portions and from the bottom of the filling agent mass toward the top portion. The upper and inner portions of the filling agent mass are kept soft and fluid so as to permit the escape of any gas inclusions present therein. The gases are easily vented either through the small opening in the neck of the shell 7 or through an opening (not shown) provided in the space above the thin layer of inert agent 3.

An advantage of maintaining the upper part of the filling agent mass in a soft condition is that good firm contact may be maintained between the wall of the shell 7 and the filling mass, which might otherwise not be pos sible due to the shrinkage of the material brought about by the heat treatment.

After the filling agent 2 has completely solidified, the detonator may be inserted into the shell 7 or the shell 7 may be removed and replaced by a detonator or equal measurements or similar dimensions. In this connection it is preferable to follow the first mentioned method, that is, to insert the detonator into the shell 7.

For the purpose of better understanding the invention, an example is described, but it is to be understood that the invention is not limited by the example but is to be limited only by the appended claims.

Exantple A casing made of stainless steel of oval shape is filleo with water. An electrode is inserted into the casing to a height about the middle of the height of the casing. When the circuit is closed and electric current flows through, phosphorus is admitted through a feed line in the absence ofair. When the flow of phosphorus reaches the level of the two poles of the electrode, electric current stops flowing because of the diflference in electrical conductivity between water and phosphorus. When the easing has been completely filled, then the level-determining means is removed and a detonator casing is screwed firmly into the top of the oval body. The detonator casing is filled with water and provided with a conventional heating element. When solidification has been completed, the heating element is removed, as well as any water which is still present in the detonator shell, and the detonator is screwed into the shell.

The term hollow body has been used throughout the specification to indicate a container, shell or casing. This term has been used even when the hollow body or casing is in the filled condition, as for example filled with the inert agent. This has been done so as to avoid confusion.

I claim:

1. Process for filling shells with an explosive agent under exclusion of air and thereafter effecting the substantially uniform solidification of said explosive agent, which comprises filling said shell with Water capable of conducting an electric current to at least a predetermined level, supplying an explosive agent having an electrical conductivity differing from that of said water to said shell containing said water under exclusion of air so as to displace said water to above said predetermined level, by the steps of maintaining an electric current through said water at said predetermined level so that when the water is displaced above that level by said explosive agent the said current is maintained through said explosive agent, controlling the supply of said explosive agent to said shell in dependence on the change of current passed through the Water and said explosive agent, supplying heat in the absence of air to the central and upper portions of said explosive agent, whereby the central and upper portions of said explosive agent are heated and the outer and lower portions of said explosive agent have substantially completely solidified, and thereafter in the absence of air corn pleting the solidification.

2. Process'for filling shells with an explosive agent under exclusion of air and thereafter effecting the substantially uniform solidification of said explosive agent, which comprises filling said shell with water capable of conducting an electric current to at least a predetermined level, supplying an explosive agent having an electrical conductivity differing from that of said water to said shell containing said water under exclusion of air so as to displace said water to above said predetermined level, by the steps of maintaining an electric current through said water at said predetermined level so that when the water is displaced above that level by said explosive agent the said current is maintained through said explosive agent, controlling the supply of said explosive agent to said shell in dependence on the change of current passed through the water and said explosive agent, inserting a second shelllike body into said explosive agent, supplying heat in the absence of air to the central and upper portions of said explosive agent disposed in said first-mentioned shell, whereby the residual amount of Water is vaporized and removed, and supplying heat through said second shelllike body whereby solidification of said explosive agent occurs in the bottom and outer portions and thereafter in the outer and inner portions of said explosive agent filling said shell.

3. Process for filling shells with an explosive agent containing phosphorus under exclusion of air and thereafter eifecting the substantially uniform solidification of said explosive agent, which comprises filling said shell with water capable of conducting an electric current to at least a predetermined level, supplying an explosive agent containing phosphorus, having an electrical conductivity differing from that of said water to said shell containing said water under exclusion of air so as to displace said water to above said predetermined level,'by the steps of maintaining an electric current through said water at said predetermined level so that when the Water is displaced above that level by said explosive agent containing phosphorous the said current is maintained through said explosive agent containing phosphorus, controlling the supply of said explosive agent containing phosphorus to said shell in dependence on the change of current passed through the water and said explosive agent containing phosphorus, whereby said explosive agent containing phosphorus fills said shell to above said predetermined level, a thin layer of water remaining on top of said explosive agent containing phosphorus, inserting through said explosive agent containing phosphorus a second shell-like body, supplying heat in the absence of air to said second shell-like body whereby the central and upper portions of said explosive agent containing phosphorus filling said first-mentioned shell are heated, removing the residual water by evaporation, and allowing the explosive agent containing phosphorus to solidify gradually from the outer and bottom portion to the inner and upper portions of said explosive agent containing phosphorus.

4. Apparatus for filling a shell with an explosive agent under exclusion of water, comprising a shell serving as a container for water and thereafter for an explosive agent having an electrical conductivity differing from that of water and for effecting substantial uniform solvency of said explosive agent, means for feeding said explosive agent to said container so as to displace the water filling said container therefrom, electrical means for controlling the feed of said explosive agent, an electric circuit including said electrical means, a source of current and means for conducting current through said Water and said explosive agent at least one electrode positioned at a predetermined level within said container, said means for controlling the feed of said explosive agent being responsive to the change in current conducted through said water and said explosive agent for cutting off the supply of said explosive agent, and means for supplying heat in the absence 7 of air to the central and upper regions of said shell disposed within said shell.

5. Apparatus according to claim 4, wherein said means for supplying heat include a second shell-like body which may be securely fastened into the upper portion of said first-mentioned shell.

6. Apparatus according to claim 5, wherein said second shell-like body is provided with means for effecting an indirect heat exchange.

7. Apparatus according to claim 6, wherein said second shell-like body is provided with an opening for the escape of gases and any water possibly remaining in said shell.

8. Apparatus according to claim 5, wherein said second shell-like body constitutes a detonator shell.

9. Process for filling shells with an explosive agent containing phosphorus which comprises maintaining a body of water within the shell to at least a predetermined level, maintaining an electrode within the shell in the water at the level to which the shell is to be filled with the explosive, passing an electric current from the electrode through the water, passing an explosive agent containing phosphorus having an electrical conductivity differing from 8 that of water into the shell so as to fill the shell and displace the water, interrupting the supply of the explosive when the electric current passing from the electrode changes as caused by the explosive contacting the electrode, inserting a second shell-like body into the upper central portion of the explosive and applying heat to the explosive through said second shell-like body to thereby allow the explosive to solidify gradually from the outer and lower portions to the inner and upper portions.

Great Britain Feb. 14, 

9. PROCESS FOR FILLING SHELLS WITH AN EXPLOSIVE AGENT CONTAINING PHOSPHORUS WHICH COMPRISES MAINTAINING A BODY OF WATER WITHIN THE SHELL TO AT LEAST A PREDETERMINED LEVEL, MAINTAINING AN ELECTRODE WITHIN THE SHELL IN THE WATER AT THE LEVEL TO WHICH THE SHELL IS TO BE FILLED WITH THE EXPLOSIVE, PASSING AN ELECTRIC CURRENT FROM THE ELECTRODE THROUGH THE WATER, PASSING AN EXPLOSIVE AGENT CONTAINING PHOSPHORUS HAVING AN ELECTRICAL CONDUCTIVITY DIFFERING FROM THAT OF WATER INTO THE SHELL SO AS TO FILL THE SHELL AND DISPLACE THE WATER, INTERRUPTING THE SUPPLY OF THE EXPLOSIVE WHEN THE ELECTRIC CURRENT PASSING FROM THE ELECTRODE CHANGES AS CAUSED BY THE EXPLOSIVE CONTACTING THE ELECTRODE, INSERTING A SECOND SHELL-LIKE BODY INTO THE UPPER CENTRAL PORTION OF THE EXPLOSIVE AND APPLYING HEAT TO THE EXPLOSIVE THROUGH SAID SECOND SHELL-LIKE BODY TO THEREBY ALLOW THE EXPLOSIVE TO SOLIDIFY GRADUALLY FROM THE OUTER AND LOWER PORTIONS TO THE INNER AND UPPER PORTIONS. 